利用Libev写一个简单的client和server程序

古城微笑少年丶 2022-08-10 03:41 143阅读 0赞

**利用Libev写一个简单的client和server程序**

**common.h程序：**

#ifndef _COMMON_H_
    #define _COMMON_H_
    
    #include <unistd.h>
    #include <fcntl.h>
    #include <sys/types.h>
    #include <sys/socket.h>
    #include <arpa/inet.h>
    #include <strings.h>
    #include <cstdlib>
    #include <cstdio>
    #include <cstddef>
    #include <string>
    
    namespace common{
    
    #define D(exp,fmt,...) do {                     \
            if(!(exp)){                             \
                fprintf(stderr,fmt,##__VA_ARGS__);  \
                abort();                            \
            }                                       \
        }while(0)
    
    static void setnonblock(int fd){
        fcntl(fd,F_SETFL,fcntl(fd,F_GETFL) | O_NONBLOCK);
    }
    static void setreuseaddr(int fd){
        int ok=1;
        setsockopt(fd,SOL_SOCKET,SO_REUSEADDR,&ok,sizeof(ok));
    }
    
    static void setaddress(const char* ip,int port,struct sockaddr_in* addr){
        bzero(addr,sizeof(*addr));
        addr->sin_family=AF_INET;
        inet_pton(AF_INET,ip,&(addr->sin_addr));
        addr->sin_port=htons(port);
    }
    
    static std::string address_to_string(struct sockaddr_in* addr){
        char ip[128];
        inet_ntop(AF_INET,&(addr->sin_addr),ip,sizeof(ip));
        char port[32];
        snprintf(port,sizeof(port),"%d",ntohs(addr->sin_port));
        std::string r;
        r=r+"("+ip+":"+port+")";
        return r;
    }
    
    static int new_tcp_server(int port){
        int fd=socket(AF_INET,SOCK_STREAM,IPPROTO_TCP);
        D(fd>0,"socket failed(%m)\n");
        setnonblock(fd);
        setreuseaddr(fd);
        sockaddr_in addr;
        setaddress("0.0.0.0",port,&addr);
        bind(fd,(struct sockaddr*)&addr,sizeof(addr));
        listen(fd,64); // backlog = 64
        return fd;
    }
    
    static int new_tcp_client(const char* ip,int port){
        int fd=socket(AF_INET,SOCK_STREAM,IPPROTO_TCP);
        setnonblock(fd);
        sockaddr_in addr;
        setaddress(ip,port,&addr);
        connect(fd,(struct sockaddr*)(&addr),sizeof(addr));
        return fd;
    }
    
    }; // namespace common
    
    #endif // _COMMON_H_

echo\_client.cc:

#include "ev.h"
    #include "common.h"
    
    static void do_connected(struct ev_loop* reactor,ev_io* w,int events){
        close(w->fd);
        ev_break(reactor,EVBREAK_ALL);
    }
    
    int main(){
        struct ev_loop* reactor=ev_loop_new(EVFLAG_AUTO);
        int fd=common::new_tcp_client("127.0.0.1",34567);
        ev_io io;
        ev_io_init(&io,&do_connected,fd,EV_WRITE);
        ev_io_start(reactor,&io);
        ev_run(reactor,0);
        close(fd);
        ev_loop_destroy(reactor);
        return 0;
    }

echo\_server.cc:

#include "ev.h"
    #include "common.h"
    
    static void do_accept(struct ev_loop* reactor,ev_io* w,int events){
        struct sockaddr_in addr;
        socklen_t addr_size=sizeof(addr);
        int conn=accept(w->fd,(struct sockaddr*)&addr,&addr_size);
        std::string r=common::address_to_string(&addr);
        fprintf(stderr,"accept %s\n",r.c_str());
        close(conn);
    }
    
    int main(){
        struct ev_loop* reactor=ev_loop_new(EVFLAG_AUTO);
        int fd=common::new_tcp_server(34567);
        ev_io w;
        ev_io_init(&w,do_accept,fd,EV_READ);
        ev_io_start(reactor,&w);
        ev_run(reactor,0);
        close(fd);
        ev_loop_destroy(reactor);
    }